Research And Design Of New Energy Vehicle Battery Management System

With the rapid construction of UHVDC transmission systems and the vigorous development and integration of new energy sources,the characteristics of the power grid that " Strong DC Weak AC" are becoming increasingly apparent.Due to the power grid’s increasing demand for large-capacity dynamic reactive power backup,the State Grid has installed a certain number of new-generation synchronous condensers in the converter stations of the UHVDC transmission system.These synchronous condensers can provide fast and large-capacity reactive power support to the grid when grid failure leads to reactive power fluctuates,thereby stabilizing the grid voltage.The operating characteristics of the new generation of synchronous condenser are different from the conventional synchronous motors,so it is extremely necessary to establish the relevant research model of the new generation of synchronous condenser and conduct a study on its transient characteristics.This article takes the operation of synchronous condenser that connected to the grid in an ultra-high voltage one machine infinite bus system as the background.In this background,we have established a field-road-network-control coupling model of synchronous condenser,and analyzed its operating characteristics during coupling control.First,considering the non-linear factors such as magnetic field saturation,distortion and skin effect of synchronous condenser,transformer,transmission system parameters and operation control,we have established a time step finite element mathematics model of the field-circuit-network-control coupling synchronous condenser,which can realize the comprehensive coupling of the twodimensional transient electromagnetic field-external circuit-grid-control system of the motor.Second,we established a new generation of synchronous condenser’s field model,and verified the correctness of the model by calculating the no-load characteristics of the synchronous phase modulation airport model;we also established a static self-excited excitation system model of the synchronous condenser based on PID control and an ultra-high voltage single machine infinity system model to realize the parallel operation of the synchronous condenser;meanwhile,a steady-state operation model of synchronous condenser in ultra-high voltage single-machine infinite system was established.Through the established field-road-network-control coupling synchronous condenser steady-state operating characteristics simulation model,we can clearly analyze the operating characteristics of the synchronous condenser during the steady-state operation of the system.Finally,by establishing field-road-network-controlled coupled synchronous condenser transient operating characteristics simulation model,we can analysis the excitation output,reactive power and magnetic field distribution of the synchronous condenser under different fault types and different fault depths when it respectively occurs’ three-phase short circuit,two-phase ground,single-phase ground and twophase short circuit of different depths at the same point in the power grid.Meanwhile,the supporting effect of the synchronous condenser installed in the power grid on the grid voltage is compared and analyzed.The field-road-network-control coupled synchronous condenser operating characteristics simulation model laid the foundation for the research of the synchronous condenser operating characteristics.